It wasn't me but happened on one of our helicopters. Lost power during a ship hoist due to salt water causing a salt buildup on compressor blades resulting in compressor stall. Man still attached to cable, so it was cut to prevent yanking him off the boat and into the rotors.
Hoisting into tall trees in mdt turbulence (crashes always seem to happen in bad weather), cable wrapped around tree branch. With man on the hook, the cable was too tight to do much. Man on hook swung to tree, climbed up a bit and unloaded cable, moved helicopter to free cable. Very nearly had to cut that cable.
Another incident that very nearly resulted in cutting the cable. Hydraulic hoist started random rapid moevements while man on high (>100') hoist. Barely able to get him to the ground. Once on ground (he hit hard), excess cable peeled out so cutting unneccessary. If cable didn't peel out, man could have been yanked off harshly only to be smacked into the ground yet again.
Small price to pay, low weight, don't know why you wouldn't have one.